In BBC’s Sherlock, what is the name of Sherlock Holmes’s childhood best friend?

Sherlock Holmes’s childhood best friend in BBC’s Sherlock is Victor Trevor.

Victor is mentioned during the series 3 episode “The Final Problem,” which explores Sherlock’s childhood and the trauma surrounding his sister Eurus. Sherlock remembers Victor as a close friend before a tragedy caused by Eurus transformed the Holmes family.

The name is significant because it links Sherlock’s adult behavior to events much earlier in his life. His memories of Victor are incomplete and emotionally charged, and the episode uses them to reveal why Sherlock created a protective mental narrative around his childhood.

Victor Trevor should not be confused with Sebastian Moran, a criminal connected with Moriarty, or James Sholto, John Watson’s former military colleague. Those characters belong to Sherlock’s adult investigations and have no role as his childhood best friend.